Performance of an Aeolian Materials Sampler for the Determination of Amount of Coarse Organic Matter Transported during Wind Erosion Events in the Sahel, West Africa(<Special Issue>International Symposium: Challenges to Soil Degradation Towards Sustaining Life and Environment, Tokyo Metropolitan University Symposium Series No.2, 2009)

抄録

In the Sahel region of West Africa, wind erosion can affect the soil organic carbon (SOC) level through the transport of soil organic matter (SOM). Coarse organic matter (COM) is the preferentially blown fraction of SOM, which was defined in this study as free organic debris >200μm in diameter. Considering the lack of a reliable method for determining the amount of COM transported by wind, an Aeolian Materials Sampler (AMS) was designed to be used with a Big Spring Number Eight (BSNE) sampler. The performance of the AMS in determining the amount of COM transported was verified by a wind tunnel experiment and a field experiment. The wind tunnel experiment showed that the AMS accurately estimated the COM mass flux at the height of 0-0.05m using wind data and some simple equation. The field experiment showed that the COM loss from the cultivated field calculated using the conventional method (employing only the BSNE sampler) for estimating the amount of soil particles transported was not consistent with the actual value (Q value=1.25±0.23 on April 13; if Q is close to 1, it indicates that the estimated COM loss agreed with the actual value). The estimated COM loss using a combination of the AMS and BSNE samplers (new method) agreed with the actual value (Q value=1.12±0.21 on April 13). These data support the conclusion that the AMS can be used to determine the amount of COM transported during wind erosion events in the Sahel.